The battle lines have been drawn in what is shaping up to be a proxy fight between a pair of activist hedge funds and The New York Times Co.

Harbinger Capital Partners and Firebrand Partners have upped their stake in the Gray Lady to 15.6% over the past two days, and are now the largest shareholders in the publisher. Meanwhile, the war of words between the two sides is heating up, after the Times Co. said it opposed Harbinger’s proxy.

In a preliminary proxy filing, Times Co. Chairman Arthur Sulzberger “urges [shareholders] not to sign or return any proxy card that you may receive from Harbinger,” and instead to vote for the company’s own slate of investors.

Harbinger, which called the Times Co.’s move “disappointing,” shot back.

“As the company’s largest shareholder, with over 15% of the Class A shares, we are particularly concerned that the company refused to interview any of our nominees despite our repeated offers to meet at their convenience,” the Birmingham, Ala.-based hedge fund said in a statement.

“Shareholders are faced with a clear choice: to support directors that have been hand-picked by the current Board, or truly independent directors put forward by the largest shareholder who is already effecting positive change.”

Harbinger and Firebrand have hired proxy solicitor DF King, and expects to file its preliminary proxy next week.

The hedge fund group, which wants the Times Co. to focus more on its digital media business, has proffered candidates for all four of the Class A board seats. To date, the Times Co. has only nominated one. Nine of the company’s directors are elected by the Times Co.’s controlling Sulzberger family, who own its Class B shares.